Effect of dietary zinc-methionine supplementation on growth performance, nutrient utilization, antioxidative properties and immune response in broiler chickens under high ambient temperature

Dietary Zn proteinate with moderate chelation strength alleviates heat stress-induced intestinal barrier function damage by promoting expression of tight junction proteins via the A20/NF-κB p65/MMP-2 pathway in the jejunum of broilers

BACKGROUND

The aim of this study was to determine whether and how Zn proteinate with moderate chelation strength (Zn-Prot M) can alleviate heat stress (HS)-induced intestinal barrier function damage of broilers. A completely randomized design was used for comparatively testing the effects of Zn proteinate on HS and non-HS broilers. Under high temperature (HT), a 1 (Control, HT-CON) + 2 (Zn source) × 2 (added Zn level) factorial arrangement of treatments was used. The 2 added Zn sources were Zn-Prot M and Zn sulfate (ZnS), and the 2 added Zn levels were 30 and 60 mg/kg. Under normal temperature (NT), a CON group (NT-CON) and pair-fed group (NT-PF) were included.

RESULTS

The results showed that HS significantly reduced mRNA and protein expression levels of claudin-1, occludin, junctional adhesion molecule-A (JAMA), zonula occludens-1 (ZO-1) and zinc finger protein A20 (A20) in the jejunum, and HS also remarkably increased serum fluorescein isothiocyanate dextran (FITC-D), endotoxin and interleukin (IL)-1β contents, serum diamine oxidase (DAO) and matrix metalloproteinase (MMP)-2 activities, nuclear factor kappa-B (NF-κB) p65 mRNA expression level, and protein expression levels of NF-κB p65 and MMP-2 in the jejunum. However, dietary supplementation with Zn, especially organic Zn as Zn-Prot M at 60 mg/kg, significantly decreased serum FITC-D, endotoxin and IL-1β contents, serum DAO and MMP-2 activities, NF-κB p65 mRNA expression level, and protein expression levels of NF-κB p65 and MMP-2 in the jejunum of HS broilers, and notably promoted mRNA and protein expression levels of claudin-1, ZO-1 and A20.

CONCLUSIONS

Our results suggest that dietary Zn, especially 60 mg Zn/kg as Zn-Prot M, can alleviate HS-induced intestinal barrier function damage by promoting the expression of TJ proteins possibly via induction of A20-mediated suppression of the NF-κB p65/MMP-2 pathway in the jejunum of HS broilers.

Zinc intake ameliorates intestinal morphology and oxidative stress of broiler chickens under heat stress

Zinc (Zn), an essential trace element for poultry, plays a crucial role in promoting growth, improving feed conversion efficiency, enhancing antioxidant activity, and preventing disease. This study investigated the impact of different levels and sources of dietary Zn supplementation on the growth performance, intestinal morphology and antioxidant activity of broiler chickens under heat stress conditions. In this experiment, 1024 Xueshan chickens were divided into eight groups and subjected to heat stress conditions with different levels of Zn supplementation (30 mg/kg, 60 mg/kg, and 90 mg/kg) using organic or inorganic sources. Our findings indicated that dietary Zn supplementation significantly increased the feed-to-weight ratio of broilers during the experimental period under heat stress. Moreover, Zn supplementation positively increased the villus height and villus width in the jejunum and ileum at 74 and 88 days old, with the 60 and 90 mg/kg groups outperforming other groups, and organic Zn was more effective than inorganic Zn. Furthermore, Zn supplementation significantly increased serum antioxidant levels, with higher superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-px) activities, and organic Zn was more effective than inorganic Zn. This study concludes that Zn supplementation is beneficial in mitigating the detrimental impacts of heat stress on broilers. The findings suggest that employing Zn as a strategy can enhance productivity in the poultry industry by positively influencing intestinal morphology and bolstering antioxidant activity to counteract potential stress.

The beneficial effect of nanomethionine supplementation on growth performance, gene expression profile, and histopathology of heat-stressed broiler chicken

This study investigated the effects of nanomethionine (nano-meth) on performance, antioxidants, and gene expression of HSP70, HSP90 and Heat Shock factor-1 (HSF-1) from the liver, and TLR4 from the jejunum, of broiler chickens reared under normal temperatures or under heat stress. Three hundred 1-day-old chicks were randomly assigned to 5 treatment groups. Group 1 served as control. Under normal temperature, birds in group 2 received nano-meth (10 mL/L of drinking water) from d1 until the experiment ended. Group 3 birds were heat-stressed (HS) and did not receive any supplementation. Group 4 received nano-meth in the same dose from d1 old until experiment ended, and the birds were exposed to HS. Group 5 birds were HS and received supplementation of nano-meth during the HS period only. Nano-meth improved (P < 0.0001) final body weight, weight gain, feed conversion ratio, and also decreased (P < 0.0001) the effect of HS on growth performance. Reduction (P < 0.0001) in malondialdehyde and changes in antioxidant enzymes GPX and CAT activity indicated the antioxidant effect of nano-meth. Nano-meth supplementation caused an increase in the expression of HSP70 , HSP90 and HSF1, and a downregulation of TLR4 gene expression. Additionally, nano-meth-supplemented groups showed marked improvement in the histological liver structure, intestinal morphology and villus height compared to control or HS groups.

Production and Evaluation of Encapsulated Zinc Oxide on Performance, Ileal Digestibility and Zinc Transporter Gene Expression in Broiler Chicken

The present study was undertaken for the production of encapsulated zinc and its evaluation in broiler chicken diet. The process of microencapsulation involved the use of polymers, gum arabic and maltodextrin with a maximum encapsulation of efficiency of 66%. Encapsulated material contained about 20% zinc oxide (ZnO) as core material following the freeze-drying process. One hundred and ninety-two-day-old broiler chicks were distributed in four groups in six replications having eight birds in each. The four groups comprised control (inorganic source of zinc), En-Zn-100 (encapsulated zinc at 100% of control), En-Zn-50 (encapsulated zinc at 50% of control), and Org-Zn-50 (Zn-methionine at 50% of control). The experiment was carried out for 35 days following standard management practices. The live weight gain, feed intake and FCR were comparable among groups. Plasma and muscle zinc (ppm) content was unaffected by the level or source of zinc supplementation. The zinc apparent ileal digestibility coefficient was significantly (P < 0.05) higher in En-Zn-50 fed groups, while crude protein digestibility was not affected by the level or form of Zn supplementation. Bone weight, length, and zinc content were comparable, and bone ash content was significantly different among the groups. Relative expression of ZnT2 was significantly upregulated in encapsulated zinc-fed groups. From the study, it could be concluded that supplementation of zinc either as encapsulated or organic form at 50% of inorganic source (ZnO) could be sufficient to maintain the growth performance, serum, tissue and bone mineral content in broiler chicken.

Replacing biochar with mineral premix and its interaction with vitamin C on laying hen production and egg quality factors

This researchers focused at how adding vitamin C (VC) to biochar and replacing it with a mineral supplement affected egg quality and laying hen performance. 50 experimental units were created from 400 laying hens using a 5 × 2 factorial treatment design (10 treatments, 5 repeats, and 8 laying hens per repetition). Biochar levels (0, 25, 50, 75, and 100% replacement with mineral supplements of diet) and VC levels (0 and 100 mg/kg of diet) were some of the studied variables. The results showed that different experimental diets had no significant effect on performance parameters (feed intake, feed conversion ratio, daily weight gain, egg weight, egg production, and egg mass) of laying hens. In the whole of experiment (50-62 weeks of age), dietary treatments had no influence on egg albumen %, Haugh unit, albumen index, yolk %, yolk index, yolk color, egg shell thickness, or egg shell ash. The results revealed that biochar, due to its availability and easy production, can replace mineral supplements in laying hens' diet, with no adverse effects on productive performance and egg quality traits.

Efficacy of Dietary Supplementation with Zinc-Chromium Mixture, Organic Selenium, or Their Combinations on Growth Performance, Carcass Traits, and Blood Profiles of Broilers under Heat Stress Conditions

To determine the effects of organic selenium (0.0-0.6 mg and 0.9 mg Se/Kg diet) and Zn-Cr mixture (100 mg Zn/Kg diet plus 1.5 mg Cr/Kg diet) on broiler chicken performance, carcass traits, blood hematology, and biochemistry under heat stress conditions, this study was conducted. Under temperatures between 30.21 to 31.82 °C, 240 broiler chickens (Ross-308), which were 7-day-old, were randomly assigned to one of six treatments: T1 (control), T2 (100 mg Zn per kg of diet and 1.5 mg Cr per kg of diet), T3 (0.6 mg Se per kg of diet), T4 (0.9 mg Se per kg of diet), T5 (100 mg Zn, 1.5 mg Cr and (LSe), and T6 (100 mg Zn, 1.5 mg Cr and (HSe)). At 35 days old, the chicks fed a diet containing Zn-Cr with low or high organic selenium (organic-Se) outweighed the control group in terms of live body weight, weight gain, and feed conversion ratio (p < 0.05). In comparison to the control treatment, birds fed diets supplemented with Zn-Cr or organic-Se (LSe, HSe) significantly increased their serum levels of total protein and total antioxidant capacity. However, these additives resulted in a decrease (p < 0.01) in their serum levels of triglycerides, total cholesterol, low-density lipoprotein (LDL) cholesterol, creatinine, and uric acid. Together, it was found that trace elements (Zn-Cr and organic-Se) may greatly lessen the impacts of heat stress on broilers by promoting growth performance and boosting metabolic processes.

Ramifications of Heat Stress on Rabbit Production and Role of Nutraceuticals in Alleviating Its Negative Impacts: An Updated Review

Heat stress has become a widespread concern worldwide, which is a major environmental stress that causes substantial economic loss in the rabbit industry. Compared to other agricultural animals, rabbits are more sensitive to heat stress as they have fewer sweat glands and a thicker coat of fur, increasing the heat dissipation complexity. Thus, heat stress hurts rabbits' productivity, meat quality, reproductive performance, antioxidative properties, immune responsiveness, intestinal histomorphology, and microbiome. Nutraceuticals include vitamins, minerals, antioxidants, organic acids, fatty acids, probiotics, prebiotics, synbiotics, enzymes, and medicinal plants due to the possible impacts on maintaining common biological situations, strengthening immune response, and preventing illness, which ultimately led to an increase in productivity. Nutraceuticals have recently attracted a lot of attention to alleviate the adverse impacts of heat stress in rabbit farms. The objective of the current review is to provide acquaintance with the recent findings about the impact of heat stress on rabbit productivity and the advantages of dietary supplementation of nutraceuticals in mitigating it.

Effect of organic and inorganic manganese supplementation on performance and eggshell quality in aged laying hens

BACKGROUND

Manganese (Mn) is an important trace element for laying hen's nutrition, which is required in small amounts in the diet. Its deficiency results in lowered production performance and eggshell quality.

OBJECTIVES

This experiment was conducted to investigate the influence of different sources and levels of Mn on egg production performance and eggshell quality in aged laying hens.

METHODS

A total of 720, 83-week-old Hy-Line W-36 laying hens were fed a non-Mn supplemented basal diet for 4-week (to ime Mn-exhaustion of body) and then were allocated to a completely randomized design with 10 treatments, six replicates and 12 birds each. Concentration of Mn in the non-Mn supplemented basal diet was 10.34 mg/kg (treatment 1), the added doses of dietary Mn were included 30, 60, and 90 mg/kg of three different sources (Mn-oxide, Mn-sulphate, and Mn-organic) for treatments 2-10, respectively. The experiment lasted for 12 week.

RESULTS

Dietary supplementation with either organic or inorganic Mn sources significantly enhanced egg production (EP), egg mass (EM), feed conversion ratio (FCR), and relative eggshell weight (RESW) compared with the non-Mn supplemented diet. However, the experimental diets did not influence feed intake (FI), egg weight, and other eggshell quality traits. Based on the broken line regression models, the performance traits were optimized at 30-40 mg/kg Mn concentration when supplemented by Mn-sulphate or Mn-organic. Although, it was 80-90 mg/kg when supplemented by Mn-oxide. The relative bio-efficacy of inorganic Mn sources include Mn-oxide and Mn-sulphate in compare with Mn-organic were estimated 45% and 87% (for EP trait), 30% and 94% (for EM trait), 36% and 99% (for FCR trait), and 37% and 78% (for RESW trait), respectively.

CONCLUSIONS

In the aged laying hens, Mn requirement is higher than the NRC's recommendation. Sulphate and organic sources of Mn are more effective than Mn-oxide.

Growth-stimulating and antioxidant effects of vanillic acid on healthy broiler chickens

Background and Aim

Phytobiotics are a safe alternative to feed antibiotics in industrial poultry farming that increases productivity by stimulating various digestive enzymes to reduce the number of pathogenic microorganisms in the intestines and improve antioxidant status and immune response. This study aimed to evaluate the effect of vanillic acid in its pure form and in combination with gamma lactone on weight growth and the physiological parameters of broiler chickens.

Materials and Methods

The studies were performed on 120 Arbor Acres broiler chickens (7 days old) that were randomly divided into four groups with five replicates (cages) and six birds per replicate. The control group was fed the basal diet (BD) only. Group I was fed the BD + gamma lactone (average dose 0.07 mL/animal/day). Group II was fed the BD + vanillic acid (average dose 0.07 mL/animal/day). Group III was fed the BD + gamma lactone + vanillic acid in a 1:1 ratio (average dose 0.07 mL/body/day). Live weight of broiler chickens for all group was assessed at the end of each period (age of 7, 14, 21, 28, 35, 42 days). At the end of the experiment (on day 42), 10 broilers with an average live weight were selected for blood sampling from the axillary vein.

Results

The results showed a growth-promoting effect of vanillic acid when fed with a diet free of synthetic antioxidants. Groups I and II had increased live weights throughout the entire experiment and a significant increase at the end of the experiment (8.2%-8.5%; p ≤ 0.05) compared to the control group. Toxic effects were not found in the biochemical blood serum analyses of Groups II and III. The metabolic processes in the experimental groups were intensified, especially in the enzyme associated with amino acid metabolism (gamma-glutamyl transferase) in Groups I and III (p ≤ 0.05). Vanillic acid, whether fed alone or in combination with gamma lactone, exhibited high antioxidant activities, protected cells from oxidative damage by inducing total antioxidant, catalase, and superoxide dismutase activities (p ≤ 0.05), and reduced the level of malondialdehyde (p ≤ 0.05) measured. No significant changes in the morphological blood parameters were found.

Conclusion

The use of vanillic acid alone and in combination with gamma lactone increases the digestive enzyme activities in blood plasma, increases body weight, and has a positive effect on lipid metabolism and the antioxidant status of broiler chickens. These findings indicate the significant potential use of vanillic acid and gamma lactone in poultry due to their antioxidant properties.

Potentials of Dietary Zinc Supplementation in Improving Growth Performance, Health Status, and Meat Quality of Broiler Chickens

The demand for chicken meat is on the rise, necessitating high level of production and efficient feed conversion which to a certain extent can be actualized by the use of specific trace minerals like zinc (Zn). Zn is a part of several enzymes involved in the metabolism of protein, fat, carbohydrates, and nucleic acids. In addition, Zn has antioxidant properties and is vital for hormone function, including growth, pancreatic, and sex hormones. Its deficiency in animals is characterized by poor fertility, decreased feed intake, poor growth, testicular atrophy, and weakened immunity. Nano-Zn sources have been shown to be more bioavailable than conventional zinc (organic and inorganic) sources. Zn from organic sources, on the other hand, has higher bioavailability than Zn from inorganic sources. Furthermore, Zn supplementation promotes growth, enhances antioxidant capacity, modulates the immunity, and improves health indices in broiler chickens. Published studies have demonstrated that Zn supplementation has the potential to improve carcass yield and meat quality in broilers with various research contradictions. However, a clear understanding of the role of Zn in broiler nutrition is still lacking, necessitating further research. As a result, the purpose of this review was to highlight the influence of Zn (organic or inorganic) supplementation on growth, blood characteristics, antioxidant status, immune responses, Zn tissue/fecal concentrations, intestinal villus histomorphology, and meat quality of broiler chickens as well as Zn bioavailability to understand the role of Zn in broiler nutrition, resolve contradictory research results, and identify knowledge gaps. Understanding the role of dietary Zn in broiler chicken nutrition and meat quality will avail important suggestion on policy advancements and sustainable use of Zn in the broiler chicken industry.

Implication of apoptosis and oxidative stress in mitigation of ivermectin long-term hazards by zinc nanoparticles in male rabbits

Ivermectin is the medication of choice for treating human onchocerciasis and is used in veterinary medicine to treat a variety of ectoparasites and endoparasites. This study was designed to investigate the effects of zinc nanoparticles (ZnNPs) on the fertility of male rabbits exposed to experimental ivermectin (IVM) intoxication. A total of 72 mature male rabbits were equally divided into 4 groups (n = 18). The first group (CTR) served as control; the second group (IVM) received subcutaneous injection of IVM (0.2 mg/kg body weight); the third group (ZnNPs) fed on zinc nanoparticles (60 mg/kg diet); and the fourth group (ZnNPs + IVM) were administered IVM and zinc nanoparticles at the same doses. The experiment lasted for 9 weeks. Results revealed that IVM-intoxicated rabbits showed impaired growth performance parameters, including body weight, total body weight gain (TBWG), total feed intake (TFI), and feed conversion ratio (FCR). Moreover, carcass characteristic and fertility parameters (including semen quality parameters and testosterone levels) were also impaired after IVM administration. Additionally, testicular malondialdehyde (MDA) and antioxidant (reduced glutathione, superoxide dismutase, catalase) levels as well as the histopathology and immunohistochemical expression of caspase 3 and PCNA in the testes and epididymis were detrimentally affected. On the contrary, ZnNP administration efficiently improved most of these parameters in IVM-intoxicated rabbits. In conclusion, ZnNPs exhibited promising ability for improving the growth and fertility status of rabbits and reducing the deleterious effects of IVM possibly through the suppression of apoptotic and oxidative pathways.

Effects of dietary organic or inorganic iron concentrations on productive performance, egg quality, blood measurements, and tissue iron concentrations in aged laying hens

The objective of the current experiment was to investigate the effects of dietary organic or inorganic iron (Fe) concentrations on productive performance, egg quality, blood measurements, and tissue Fe concentrations in aged laying hens. A total of three hundred fifty 60-week-old Hy-Line Brown laying hens were allotted to one of five dietary treatments with seven replicates. Each replicate had 10 consecutive cages. Organic Fe (Fe-Gly) or inorganic Fe (FeSO₄ ) was added to the basal diet at the levels of 100 or 200 mg/kg Fe. Diets were fed on an ad libitum basis for 6 weeks. Results indicated that supplementation of organic or inorganic Fe in diets increased (p < 0.05) eggshell color and feather Fe concentrations compared with no supplementation of Fe in diets. An interaction was found (p < 0.05) between Fe sources and supplemental levels in diets for egg weight, eggshell strength, and Haugh unit. Hens fed diets supplemented with organic Fe had greater (p < 0.05) eggshell color and hematocrit than those fed diets supplemented with inorganic Fe. In conclusion, dietary supplementation of organic Fe increases the eggshell color of aged laying hens. High supplemental levels of organic Fe in diets improve egg weight in aged laying hens.

Effects of Zinc Oxide Nanoparticles on the Performance of Broiler Chickens Under Hot Climatic Conditions

This study aimed to investigate the effects of different levels of zinc oxide nanoparticles on broilers' performance, nutrient digestibility, carcass criteria, and blood biochemistry. A total of 120 1-day-old unsexed broiler chickens (Ross 308) were fed zinc oxide nanoparticles at different levels (0, 20, 40, or 60 mg/kg) in their diets. Each treatment included 6 replicate pens with 5 birds each. The experiment lasted 42 days. The brooding temperatures were 37.8 °C, 35.8 °C, and 29.9 °C during 1-10 days, 11-21 days, and 22-42 days of age, respectively. The results revealed that dietary supplementation of nanoparticles of zinc oxide at 20, 40, and 60 mg/kg diet significantly improved body weight, body weight gain, and feed conversion ratio showing linear effects (P < 0.05) compared to the birds fed the control diet under hot climatic conditions. Dietary addition of zinc oxide nanoparticles at 20, 40, and 60 mg/kg linearly increased (P < 0.05) the nutrient digestibility of crude protein, crude fiber, and ether extract compared to the control group. Birds fed the supplemented diets had improved liver and kidney function without any negative effects on zinc, inorganic phosphorus, triiodothyronine (T₃), and thyroxine (T₄) levels in serum compared to the control. Diets supplemented with zinc oxide nanoparticles linearly (P < 0.05) improved the dressing percent and reduced abdominal fat percent compared to the control group. In view of the above findings, it can be concluded that dietary supplementations of zinc oxide nanoparticles at 20, 40, and 60 mg/kg resulted in improved growth performance, nutrient digestibility, carcass criteria, and liver and kidney functions of broiler chickens under hot environmental conditions.

Meta-analysis of Zinc Supplementation on Laying Performance, Egg Quality Characteristics, and Blood Zinc Concentrations in Laying Hens

There are inconsistent results on the influence of zinc (Zn) supplementation levels on productive indices of laying hens. This study, therefore, uses meta-analysis to synthesis evidence on the effect of inclusion of Zn in chicken diets on performance, egg quality, and blood Zn status of laying hens. Eleven studies were identified and used to analyze the effect of diets with or without Zn supplementation on feed intake, feed conversion ratio (FCR), hen day egg production (HDEP), egg weight (EW), egg mass (EM), Haugh unit (HU) scores, eggshell thickness (EST), eggshell weight (ESW), and blood Zn concentrations in laying hens. Data extracted from the 11 studies included in the meta-analysis were pooled using a random-effects model and expressed as standardized mean differences (SMDs) at a 95% confidence interval (CI). Results indicate that dietary Zn supplementation reduced FCR (SMD =  - 0.50 g feed/g egg; 95% CI: - 0.68 to - 0.31) and increased HDEP (SMD = 0.33%; 95% CI: 0.18 to 0.48), EW (SMD = 0.14 g; 95% CI: 0.03 to 0.25) and EM (SMD = 0.58 g/hen/day; 95% CI: 0.22 to 0.95), HU (SMD = 0.64; 95% CI: 0.42 to 0.85), EST (SMD = 0.84 mm; 95% CI: 0.45 to 1.23), and plasma Zn concentration (SMD = 4.20 mg/dl; 95% CI: 2.99 to 5.40) compared with the controls. In contrast, feed intake and ESW were not significantly different from controls. Restricted subgroup analysis indicated that chosen moderators (age of hen, inclusion level, chicken breed/strain, and supplementation duration) influenced the results of this meta-analysis. There was evidence of significant heterogeneity, and meta-regression indicated that moderators explained most of the sources of heterogeneity. We conclude that dietary zinc supplementation had positive effect on feed conversion ratio, laying performance, aspects of egg quality traits, and blood zinc concentrations in laying hens. The findings from this meta-analysis will help in policy advancements and sustainable use of zinc in the egg production industry.

A perspective review on the effect of different forms of zinc on poultry production of poultry with special reference to the hazardous effects of misuse

Zinc (Zn) is a unique micro-mineral because it is an essential component in many enzymes such as superoxide dismutase, carbonic anhydrase, and alkaline phosphatase, as well as being important for regulation of proteins and lipids metabolism, and sex hormones. This mineral is applied in poultry production in three forms; inorganic, organic, and nanoparticle form. The nano-form of Zn is preferable in application to other conventional forms with regard to absorption, bioavailability, and efficacy. Broilers fed on diets supplemented with Zn showed improvement of growth performance, carcass meat yield, and meat quality. In addition, Zn plays an important role in enhancing of both cellular and humeral immune responses, beside its antimicrobial and antioxidant activities. In laying hens, dietary addition of Zn improves the eggshell quality and the quantity of eggs. Moreover, Zn has a vital role in breeders in terms of improving the egg production, fertility, hatchability, embryonic development, and availability of the hatched chicks. Therefore, this review article is focused on the effects of using Zn on the performance and immunity of poultry, as well as its antimicrobial and antioxidant properties with special reference to the hazardous effects of the misusing of this mineral.

Effect of Dietary Zinc Methionine Supplementation on Growth Performance, Immune Function and Intestinal Health of Cherry Valley Ducks Challenged With Avian Pathogenic Escherichia coli

This study was carried out to evaluate the effects of supplemental zinc methionine (Zn-Met) on growth performance, immune function, and intestinal health of meat ducks challenged with avian pathogenic Escherichia coli (APEC). A total of 480 1-day-old Cherry Valley male ducks were randomly assigned to 8 treatments with 10 replicates, each replicate containing 10 ducks. A 4 × 2 factor design was used with four dietary zinc levels (0, 30, 60, 120 mg Zn/kg in the form Zn-Met was added to the corn-soybean basal diet) and challenged with or without APEC at 8-days-old ducks. The trial lasted for 14 days. The results showed that a dietary Zn-Met supplementation significantly increased body weight (BW) of 14 days and BW gain, and decreased mortality during 7-14-days-old ducks (p < 0.05). Furthermore, dietary 30, 60, 120 mg/kg Zn-Met supplementation noticeably increased the thymus index at 2 days post-infection (2 DPI) and 8 DPI (p < 0.05), and 120 mg/kg Zn-Met enhanced the serum IgA at 2 DPI and IgA, IgG, IgM, C3 at 8 DPI (p < 0.05). In addition, dietary 120 mg/kg Zn-Met supplementation dramatically increased villus height and villus height/crypt depth (V/C) of jejunum at 2 DPI and 8 DPI (p < 0.05). The TNF-α and IFN-γ mRNA expression were downregulated after supplemented with 120 mg/kg Zn-Met in jejunum at 8 DPI (p < 0.05). Moreover, dietary 120 mg/kg Zn-Met supplementation stimulated ZO-3, OCLN mRNA expression at 2 DPI and ZO-2 mRNA expression in jejunum at 8 DPI (p < 0.05), and improved the MUC2 concentration in jejunum at 2 DPI and 8 DPI (p < 0.05). At the same time, the cecal Bifidobacterium and Lactobacillus counts were increased (p < 0.05), and Escherichia coli counts were decreased (p < 0.05) after supplemented with Zn-Met. In conclusion, inclusion of 120 mg/kg Zn-Met minimizes the adverse effects of APEC challenge on meat ducks by improving growth performance and enhancing immune function and intestinal health.

Effects of Zinc Lactate Supplementation on Growth Performance, Intestinal Morphology, Serum Parameters, and Hepatic Metallothionein of Chinese Yellow-Feathered Broilers

In poultry, organic zinc compounds have higher bioavailability than inorganic zinc sources. However, as an organic zinc source, the application of zinc lactate (ZL) on Chinese yellow-feathered broilers has been rarely reported. Hence, the present study aimed to investigate the effects of ZL supplementation on growth performance, small intestinal morphology, serum biochemical parameters, immune organ index, as well as hepatic metallothionein of Chinese yellow-feathered broilers. A total of 2100 broilers (19 days old) were randomly assigned to 5 treatment groups, including the control (fed basal diet), ZL40 (basal diet plus 40 mg/kg ZL), ZL60 (basal diet plus 60 mg/kg ZL), ZL80 (basal diet plus 80 mg/kg ZL), and ZS80 (basal diet plus 80 mg/kg ZS. Each treatment group had 6 replicates with 70 chickens per replicate. Compared to the control group, the ZL40 and the ZS80 groups had a lower feed to gain ratio (P < 0.05), ZL40 group had higher duodenum and ileum villus heights (P < 0.05), and ZS80 and ZL80 groups had a lower ratio of villus height to crypt depth in the jejunum (P < 0.01). In addition, the ZL60 group had a higher concentration of total protein (P < 0.05) and activity of glutathione peroxidase (GSH-Px) (P < 0.01) compared with the ZS80 and the control groups. Interestingly, the ZL40, ZL60, and ZL80 groups all had higher levels of hepatic metallothionein than the other groups (P < 0.01). In conclusion, zinc lactate had a higher bioavailability and could be used as an alternative to zinc sulfate.

Effects of methionine as free amino acid and dipeptide on productive efficiency and meat quality of broilers under acute and chronic heat stress

Context Methionine in the form of free amino acid has been widely studied in broilers challenged by heat stress (HS). However, the effects of methionine dipeptide in broilers subjected to HS are not known. Aims To evaluate the effects of methionine as free amino acid and dipeptide on the performance, oxidative status, plasma parameters and meat quality of broilers subjected to acute and chronic HS. Methods Broilers were evaluated at the following three experimental periods: 24 h of evaluation (21–22 days of age); 10 days of evaluation (22–32 days of age); and 20 days of evaluation (22–42 days of age). Broilers were divided into two groups; one group was raised in thermal comfort, and the other group was raised in continuous HS of 30°C. In both groups, animals received a diet without methionine supplementation (MD), with supplementation of methionine as free amino acid (dl-M), and with supplementation of methionine as dipeptide (dl-MM). Key results HS reduced body weight gain after 10 and 20 days of evaluation. Broilers under HS condition fed the MD diet had the highest concentrations of thiobarbituric acid reactive substances (TBARS) at 22 days of age and carbonylated proteins (CP) at 32 days of age. At 42 days of age, broilers fed the MD diet had higher concentrations of TBARS and CP. At 32 days of age, broilers under HS had lower high-density lipoprotein and higher low-density lipoprotein concentrations. In breast meat, broilers in thermal comfort fed the dl-M or dl-MM diets had a lower cooking loss. Broilers in HS fed the dl-M diet had the lowest cooking loss. HS reduced the pH of the meat of legs. Conclusions The acute and chronic HS affect the broiler performance in different ways. Methionine supplementation contributes to reduce the effects of HS. There were no notable differences between the supplementation of dl-M or dl-MM. Implications Productivity and the quality of the chicken meat are the most important attributes of the production. The ambient temperature can influence these parameters. The methionine in its most varied forms, due to its direct and indirect antioxidant function, has been shown to be an effective source of protection for the animal in adverse conditions such as during HS.

Effect of Supplementation of Zinc-Methionine on Egg Production, Semen Quality, Reproductive Hormones, and Hatchability in Broiler Breeders

A biological study was conducted to explore the effect of zinc-methionine (Zn-Met) supplementation on productive, reproductive, and immunological response in broiler breeders. Adult healthy 45-week breeder males (192) and females (288) were used in a completely randomized design. Birds were randomly divided into four treatments consisting of six replicates and fed basal diet (control, 40 mg/kg), basal diet supplemented with Zn-Met 20 (T1), 40 (T2), and 60 mg/kg (T3). There was no effect (P > 0.05) on body weight and feed consumption among the breeders due to the supplementation of organic Zn. The T3 group had significantly (P < 0.05) higher semen volume, sperm motility, concentration, and live sperm count. The seminal plasma calcium and alkaline phosphatase activity were higher (P < 0.05), and total cholesterol and aspartate transaminase levels were low in the T3 group. Birds fed with additional supplementation of Zn (60 mg/kg) had improved both cellular and humoral immunity. Throughout the experimental period, the hen day egg production was comparable (P > 0.05) among the experimental groups. Organic Zn-supplemented group showed significant difference in both the internal and external egg qualities-albumen, yolk index, and shell thickness. The higher dose of organic Zn-fed groups had a significant difference in estrogen and progesterone concentration, and the highest testosterone concentration was observed in the T2 group. Supplementary organic Zn had a significant effect on the concentration of Zn and Cu in the seminal plasma. Serum Zn and Cu concentration was significantly increased due to the supplementation of organic zinc in both male and female breeders. The fertility and hatchability percentage were higher (P < 0.05) in the T2 group. It could be concluded that the additional supplementation of organic Zn (zinc-methionine) at 40 mg/kg to the basal diet improved the reproductive performance in broiler breeders.

The Impact of Zn, Cu and Fe Chelates on the Fatty-Acid Profile and Dietary Value of Broiler-Chicken Thigh Meat

Simple Summary

Poultry meat is deemed a product with a dietary value. The chemical composition of meat can be altered by modifying animals’ diets. Our objective was to show the impact of the addition of glycine chelates of minerals (Zn, Cu, Fe) to broiler chickens’ feed on the fatty-acid profile and dietary value of thigh meat. A positive effect was most frequently noted for Zn chelate, especially in a larger dose. The lowest levels of saturated fatty acids and atherogenic and thrombogenic indices but the highest content of polyunsaturated fatty acids n−3 and polyunsaturated fatty acids/saturated fatty acid ratios and hypocholesterolemic/hypercholesterolemic indices were noticed. The use of Cu and Fe glycine chelates was worse than Zn but did not meet the levels from the control group. These types of treatments are important in order to ensure correct functions of the body and can mitigate or even prevent the occurrence of many diseases.

Abstract

This study aimed to compare the effect of Zn, Cu and Fe glycine chelates on the proximate composition, cholesterol levels, fatty-acid profile and dietary value of the thigh meat of broiler chickens. The experiment involved three hundred and fifty Ross 308 chickens divided into seven groups. The chickens were administered Zn, Cu and Fe glycine chelates in an amount corresponding to 50% of the requirement or 25% of the requirement for 42 days. It was found that the use of Zn, Cu and Fe glycine chelates did affect the fatty acid profile and dietary value of meat. A positive impact was most frequently (p < 0.05) noted in chickens receiving Zn chelate in an amount covering 50% of the requirement: the lowest levels of SFA and atherogenic and thrombogenic indices, the highest content of PUFA n−3 and PUFA/SFA ratios and hypocholesterolemic/hypercholesterolemic indices. Positive effects were more often recorded for chickens receiving Zn in an amount corresponding to 50% of the requirement. The results did not show that the use of Cu and Fe glycine chelates can reduce the dietary value of thigh meat in broiler chickens since, generally, the outcomes were not worse than those in the control group. It should be highlighted that due to ambiguous results, it is impossible to determine a dose of Cu and Fe glycine chelate which would be more efficient for broiler chickens. However, chickens receiving chelates in amounts corresponding to 25% of the requirement showed far better results.

Effect of source and concentration of zinc on growth performance, meat quality and mineral retention in New Zealand rabbits

<p>Zinc supplementation in rabbit diet favours deposition of this mineral in meat and, therefore, contributes to satisfying the daily requirements of Zn in humans that consume it. A trial was conducted to study the effect of two sources (ZnSO₄ and Zn-methionate) and two concentrations of Zn, along with a control (without Zn supplementation), on weight gain, meat quality and muscle retention in New Zealand White (NZW) rabbits during fattening stage. Treatments were randomly assigned to 100 NZW rabbits 40 days old, in a completely randomised experimental design using a factorial arrangement of treatments (2×2+control). The experimental period was 30 d. In each experimental treatment, weight gain, feed consumption and meat quality were recorded, as well as the retention of Zn in serum, liver, loin and hind leg. Results showed no differences (<em>P</em>&gt;0.05) in weight gain and food consumption, which can be attributed to diet-added Zn sources (ZnSO₄ and Zn-methionate). Food conversion was better with the organic source at the highest concentration (<em>P</em>&lt;0.05). Regarding meat quality, no differences were found (<em>P</em>&gt;0.05) in hind legs for source effect and Zn concentration, while in loin, differences (<em>P</em>=0.02) were found in the colour parameter of L* and B* when the organic source of Zn (Zn-methionate) was supplied. Most retention of Zn on the loin occurred when a concentration of 25 mg Zn kg^–1 of Zn-methionate was added, which could be important to provide larger amounts of Zn for human consumption.</p>

Comparison of Zinc Sulfate and Zinc Threonine Based on Zn Bioavailability and Performance of Broiler Chicks

The purpose of this study was to compare zinc sulfate and zinc threonine chelate based on Zn bioavailability and performance of broiler chicks. The study was conducted in a completely randomized design with 256 day-old Ross 308 chicks and eight treatments including control treatment (no zinc supplementation), three levels of zinc sulfate and zinc threonine chelate (40, 80, and 120 mg zinc per kg feed), and a common commercial chelate (Bioplex Zn®) supply 40 mg zinc per kg feed. The results of total period showed that threonine chelate group had the highest live weight compared with other treatments and lowest feed conversion ratio belonged to 80 and 120 ppm of zinc threonine chelate (p < 0.05). Zinc threonine chelate and commercial chelate treatments had the lowest cholesterol and LDL levels compared with other treatments (p < 0.05). Zinc chelate threonine which contains 80 and 120 ppm of zinc had the highest HDL and superoxide dismutase enzymes and the lowest heterophile to lymphocyte ratio compared with other treatments (p < 0.05). Relative bioavailability of zinc threonine to zinc sulfate based on body weight, feed conversion ratio, cholesterol, LDL, HDL, superoxide dismutase enzyme, ash, and zinc content in tibia were 418.75, 173.91, 131.38, 159.43, 278.63, 193.45, 156.46, and 117.65%, respectively. According to the results of broiler performance and other traits measured in this study, it seems that the use of 80 ppm of zinc threonine chelate in the broiler diet is recommended in comparison with zinc sulfate levels and other threonine chelate levels.

Evaluation of dried papaya pomace meal in laying hen diets

In the search for alternative feed resources for laying hens, papaya pomace is available as industrial by-product but information on its nutritive value is lacking. Dried papaya pomace was included in a common laying hen diet at 0%, 2.5%, 5% and 7.5% to evaluate its effect on egg production performance, egg quality and general health parameters in Bovan brown layers. For every inclusion level, three cages with ten 20-week-old layers were used, making a total of 120 hens. The effect of dried papaya pomace inclusion on egg production, egg quality and general health parameters was evaluated. Dried papaya pomace inclusion improved egg production and laying by 6.15% and 17% respectively, while it significantly decreased feed conversion ratio by 7.5%. Eggshell weight, thickness and strength of PP5 were higher than the control by 0.3 g, 0.8 mm and 0.43 kg/cm² , respectively. There was a significant improvement in albumin weight (by 1.5 g/L), albumin height (2.1 mm), yolk weight (0.4 g/L), yolk height (0.4 mm), yolk colour (4.4 points) and Haugh unit (8 points) due to PP5 treatment. Inclusion of papaya pomace at a level of 7.5% of layers diet had negative effect on Egg production, feed conversion ratio and interior and exterior egg quality traits. Inclusion of papaya pomace affected significantly serum total cholesterol, serum triglyceride, serum low density lipoprotein, serum high density lipoprotein, aspartate aminotransferase, alanine aminotransferase and white blood cell count. However, all blood traits of the experimental animals were within the normal ranges reported for layers. Inclusion of papaya pomace in 5% of layers commercial diets improves egg production and quality without negative impact on health while decreasing feeding cost.

Effects of Replacing Inorganic with Organic Iron on Performance, Egg Quality, Serum and Egg Yolk Lipids, Antioxidant Status, and Iron Accumulation in Eggs of Laying Hens

This study compared the effects dietary organic (ferrous glycine [FG]) versus inorganic (ferrous sulfate [FS]) iron in laying hens on performance, egg quality, serum and egg yolk lipids, antioxidant status, and iron enrichment of eggs. A total of 378 Shaver White layers were allotted to 7 treatments with 6 replicates (9 birds each) from 30 to 42 weeks of age. A basal diet (19 mg iron/kg) served as control, while the other six diets were supplemented with either FS or FG to provide 30, 60, and 120 mg/kg of added iron. Dietary FG and FS treatments improved (P < 0.05) laying rate, egg weight, and egg quality of layers, relative to the control, albeit eggshell strength and eggshell calcium also deteriorated with the highest level of FS (P < 0.05). The iron treatment groups exhibited a lower serum and egg yolk levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol that accompanied by higher levels of high-density lipoprotein cholesterol and greater activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) as compared with the control (P < 0.05). The contents of malondialdehyde and protein carbonyl were conversely related to the activities SOD and GPx (P < 0.05). The serum and egg fractions (yolk, albumen, and shell) displayed gradually increases in iron contents as the level of iron increased in the diet (P < 0.05), while FG was superior to FS at all tested levels (P < 0.05). To summary, FS can be replaced by FG, with more favorable impacts on egg quality and iron enrichment.

Growth performance, tissue precipitation, metallothionein and cytokine transcript expression and economics in response to different dietary zinc sources in growing rabbits

The impact of different dietary zinc sources on the growth, serum metabolites, tissue zinc content, economics and relative expression of cytokine and metallothionein genes was evaluated in this study. A total of 120 35-day-old male New Zealand White (NZW) rabbits were randomly distributed into four dietary experimental groups with 10 replicates per group and 3 animals per replicate. The control group was fed basal diet with a Zn-free vitamin-mineral premix; the other three groups received control basal diet supplemented with 50 mg/kg level with zinc oxide (ZnO; as inorganic source), Zn-methionine (Zn-Met; as organic source) and zinc oxide nanoparticles (nano-ZnO). The results indicated that Zn-Met and nano-ZnO groups significantly improved body weight, daily weight gain (DWG), feed conversion ratio (FCR) and nutrient digestibility, as well as decreased mortality, compared to ZnO and control groups. Zn-Met and nano-ZnO significantly reduced serum total cholesterol but did not affect serum proteins and liver function. Nano-ZnO supplemented group also recorded the highest value of serum alkaline phosphatase (ALP), insulin-like growth factor (IGF-1) and lysozymes compared to other groups. Nano-ZnO supplementation had increased hepatic Zn and Cu content and decreased faecal Zn content. Also nano-ZnO group recorded higher expression levels of genes encoding for metallothionein I and metallothionein II, interleukin-2 and interferon-γ in the liver of rabbits. The findings of this study demonstrated zinc nanoparticles, and organic zinc supplementation had improved growth performance and health status of growing rabbits than inorganic zinc oxide.

Effects of free and dipeptide forms of methionine supplementation on oxidative metabolism of broilers under high temperature

Our previous studies have shown that methionine supplementation could help to attenuate the effects of heat stress on the metabolism of broiler chickens. Here we investigated for the first time the effects of methionine supplementation in the form of DL-methionyl-DL-methionine on broilers subjected to heat stress during the growth phase. Broilers were divided into two groups; one group was reared under thermoneutral conditions and the other under continuous heat stress (30 ± 1 °C, 60% relative humidity). Both groups were subdivided into three dietary treatments: a methionine-deficient (MD) diet, a diet supplemented with free methionine (DL-M), and a diet supplemented with methionine dipeptide (DL-MM). Broilers raised under chronic heat stress had lower feed intake and weight gain than broilers raised under thermoneutral conditions (P < 0.05). There were no differences in animal performance between methionine-supplemented diets (DL-M and DL-MM). Heat-stressed birds had significantly higher heterophil/lymphocyte (H/L) ratio than thermoneutral birds. Under heat stress, broilers fed DL-M and DL-MM diets had lower H/L ratio than birds fed the MD diet. Higher concentrations of carbonylated proteins and lower concentration of reduced glutathione were observed in broilers raised under heat stress. In comparing heat-stressed broilers, we found that birds fed the DL-M diet had lower concentrations of thiobarbituric acid-reactive substances and carbonylated proteins than those fed the MD diet (P < 0.05). Higher expression of glutathione peroxidase (GPX) and glutathione synthetase (GSS) genes was observed in heat-stressed broilers (P < 0.05). Under heat stress, the MD diet increased GPX expression compared with other diets. Under thermoneutral conditions, the DL-M diet resulted in the highest GSS expression. There was a negative correlation between DNA methylation and GPX and GSS expression. Our results showed that supplementation of broiler diets with free methionine or methionine dipeptide may help attenuate the effects of heat stress through enhanced activation of genes related to the glutathione antioxidant system. Methionine effects were found for gene regulation, gene expression, and post-translational processing.

Nano-sized Zinc in Broiler Chickens: Effects on Growth Performance, Zinc Concentration in Organs, and Intestinal Morphology

The effects of dietary supplementation of zinc (Zn) sources and concentrations were investigated on growth performance, absorption into tissues, fecal excretion, nutrient retention, and intestinal morphology in broilers fed a corn-soybean meal basal diet. A total of 525 one-day-old chicks (Ross 308) were assigned based on body weight to seven dietary treatments. There were five replicate pens for each treatment and 15 broilers per replicate pen. The dietary treatments included a basal diet (control, without supplementing Zn), and basal diet supplemented with Zn, as inorganic zinc sulfate (ZnS; 110 mg/kg); organic Zn-methionine (ZnM; 110 mg/kg); hot-melt extruded (HME) 25 zinc sulfate (27.5 mg/kg); HME50 zinc sulfate (55 mg/kg); HME75 zinc sulfate (82.5 mg/kg); or HME100 zinc sulfate (110 mg/kg) for 35 days in two phases (d 1-21, phase I and d 22-35, phase II). Bodyweight and feed efficiency of broiler chicks fed diets supplemented with increasing dietary concentrations of HME-Zn improved linearly during the study period (P<0.05). Compared to the control treatment, the ZnS, ZnM, and HME diets increased Zn concentrations in the serum and liver. Inorganic ZnS supply resulted in the highest Zn concentration in excreta. Increasing supplemented Zn content in diets as HME linearly increased Zn concentration in the excreta, serum, liver, and tibia. Broiler chicks fed diets supplemented with increasing concentrations of HME increased villus height (VH; linear and quadratic) of the jejunum and VH of the ileum (linear). Increasing concentrations of dietary Zn supplied as HME resulted in linearly enhanced dry matter, gross energy, and nitrogen retention of broilers on day 21. These results suggest that dietary HME-Zn at a lower level (55 ppm) shows the same growth performance as common ZnSO₄ at 110 ppm.

Effect of feeding wheat middlings and calcium lignosulfonate as pellet binders on pellet quality growth performance and lipid peroxidation in broiler chickens

Basal diets supplemented with 4 kg Ca-LS/ton of diet. Pellet quality characteristics (per cent fines, the present study was conducted to evaluate the influence of wheat middlings (WM) and calcium lignosulfonate (Ca-LS) as pellet binders on the pellet quality characteristics, growth performance, blood parameters, nutrients digestibilities, lipid peroxidation and muscle fatty acids profile in Egyptian broiler strain. A total of 3,120 broiler chicks at 1-day of age were divided randomly into three experimental treatments with eight replicates (130 each). The first treatment was fed the basal pelleted diets without any additives, the second treatment was fed diets including 50 kg WM/ton of diet and the third treatment was fed per cent pellets, and pellet durability index) were significantly improved in WM and Ca-LS treatments compared with the control. Body weight gain was significantly increased, while feed intake was significantly decreased resulting in improving of feed conversion ratio significantly in WM group in comparison with control and Ca-LS groups (p < .05). Nutrients apparent digestibility (dry matter, crude protein and crude fibre) were significantly improved by inclusion of WM compared with control and Ca-LS. Plasma total cholesterol, and uric acid concentrations were significantly decreased by dietary WM in comparison with control and Ca-LS experimental groups. Furthermore, linoleic, alpha-linolenic and arachidonic acids contents in breast muscle were significantly increased by WM and Ca-LS, while, muscle malondialdehyde concentration was significantly decreased. It could be concluded that inclusion of WM and Ca-LS can improve pellet quality characteristics, and WM (at a level of 50 kg/ton) had positive effects on growth performance, nutrients digestibilities, lipid peroxidation and fatty acids profile in Egyptian broiler strain.

Comparison the Zn-Threonine, Zn-Methionine, and Zn Oxide on Performance, Egg Quality, Zn Bioavailability, and Zn Content in Egg and Excreta of Laying Hens

The experiment was conducted to investigate the effect of supplementary zinc-threonine (Zn-Thr), zinc-methionine (Zn-Met), and zinc oxide (ZnO) on the laying performance, egg quality, Zn content in egg and excreta. One hundred and sixty hens (Hy-Line W36) were randomly divided into 10 treatments with 4 replications of 4 hens each. During the first 4 weeks, groups were fed a corn-soy basal diet without extra zinc (30.3 mg Zn/kg diet) to depletion storage zinc from the body and it was used as the control diet. During the ensuing 10 weeks from 36 to 45 weeks of age, 3 levels of 30, 60, and 90 mg Zn/kg were added to the diet by ZnO, Zn-Met, and Zn-Thr sources. Results showed that there were no significant differences between the experimental treatments in terms of egg weight, feed intake, eggshell weight, eggshell percentage, and albumen weight. In total experimental period, the supplementation of Zn-Met and Zn-Thr decreased feed conversion ratio and increased egg mass and egg production compared with ZnO 30 and 60 mg Zn/kg and control treatments (P < 0.05). The results showed that treatment effect on Zn content in egg and excreta was significant (P < 0.05). It is concluded that diets supplied with lower levels of organic Zn can maintain egg production performance, improve egg quality, enrich eggs, increase bioavailability, and reduce the negative effects of age on egg quality characteristics in laying hens compared with their oxide form.

Nutritional significance of amino acids, vitamins and minerals as nutraceuticals in poultry production and health - a comprehensive review

Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals' normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed.

Comparative Efficacy of Selected Phytobiotics with Halquinol and Tetracycline on Gut Morphology, Ileal Digestibility, Cecal Microbiota Composition and Growth Performance in Broiler Chickens

Simple Summary

Antimicrobial growth promoters (AGPs) are banned in Europe but still used in many countries including Asia. However, their indiscriminate use resulted in antibiotic-resistant bacterial strains that possibly transfer the resistant genes to the microorganisms pertinent to human health. Hence, it is essential to find alternatives that can improve the production performance in broiler chickens. In this scenario, phytobiotics or phytogenic feed additives (PFAs) are widely investigated to evaluate their influence on improving gut health, increasing digestibility, and thereby the growth performance. The present study is a continuity of our experiments on dietary inclusion of Piper betle and Persicaria odorata leaf meal and the first of its kind to evaluate the comparative efficacy of phytobiotics (Piper betle and Persicaria odorata leaf meal), with halquinol and tetracycline in broiler chickens. The current experiment findings indicated that, in comparison with the control group, either of the dietary treatments positively modulated the gut morphology, improved ileal digestibility, maintained the intestinal population of Lactobacillus and reduced the pathogenic bacteria such as Staphylococcus aureus, Salmonella, Escherichia coli, and Clostridium spp., thus improved the growth performance in broiler chickens.

Abstract

The current experiment was designed to estimate the comparative efficacy of selected phytobiotics Persicaria odorata leaf meal (POLM) and Piper betle leaf meal (PBLM) with halquinol, and tetracycline in broiler chickens. The 150-day-old broiler chickens were randomly assigned to five dietary groups. The dietary supplementation groups were the basal diet (BD), which served as the negative control (NC), and BD + 0.2 g/kg tetracycline, which served as the positive control (PC); BD + 0.03 g/kg halquinol (HAL), BD + 8 g/kg POLM (Po8), and BD + 4 g/kg PBLM (Pb4) were the treatment groups. Growth performance, gut morphology, ileal digestibility, and cecal microbiota composition were measured. On day 21, the body weight gain (BWG) was enhanced (p < 0.05) in the broiler chickens fed on phytobiotics (Po8 and Pb4) relative to the NC group, however, on day 42 and in terms of overall growth performance, BWG was enhanced (p < 0.05 in diets (Po8, Pb4, HAL and PC) in comparison with the NC group. Conversely, feed conversion ratio (FCR) was recorded reduced (p < 0.05) in Pb4, Po8, HAL, and PC group in comparison with the NC group. Supplementation of phytobiotics (Po8 and Pb4), HAL and PC, positively improved the gut morphology compared to the NC group. Furthermore, the maximum (p < 0.05) villus height (VH) in duodenum and jejunum was observed in broilers fed on diet Pb4. Supplementation of phytobiotics, HAL and PC, improved (p < 0.05) the digestibility of dry matter (DM) (except for HAL), organic matter (OM), crude protein (CP), ether extract (EE), and ash compared to the NC group. Dietary supplementation of phytobiotics (Po8 and Pb4), HAL and PC, significantly reduced the E. coli, Salmonella, and Staphylococcus aureus (except for HAL) counts compared to the NC group. However, supplementation of Pb4 resulted in significantly decreased total anaerobic bacteria and Clostridium spp. counts compared to the NC group. In addition, supplementation of phytobiotics significantly increased the Lactobacillus count compared to HAL, PC, and NC groups. In conclusion, dietary supplementation of phytobiotics improved the gut morphology, positively modulated and maintained the dynamics of cecal microbiota with enhanced nutrient digestibility, thus, increased the growth performance. Based on current results, phytobiotics could be used as an alternative to AGPs for sustainable broiler chicken production.

A comparative study on the antioxidant status, meat quality, and mineral deposition in broiler chicken fed dietary nano zinc viz-a-viz inorganic zinc

Use of nano minerals in farm animal nutrition offers considerable advantages over inorganic or organic mineral sources. But, the conventional chemical synthesis of nano minerals suffers from disadvantage of possible environmental accumulation and pollution due to the non-biodegradable materials and chemicals. This study investigated the effects of green nano-zinc (GNZ) and market nano-zinc (MNZ) with respect to the inorganic zinc (IZ) on meat quality, antioxidant status, mineral deposition, and bone development in broiler chicken. Following a 3 × 3 factorial design, nine dietary treatments were formulated by employing three levels (40, 60, and 80 ppm) and three sources (inorganic, green nano, and market nano) of zinc viz. IZ-40, GNZ-40, MNZ-40, IZ-60, GNZ-60, MNZ-60, IZ-80, GNZ-80, MNZ-80. Six replicates of broiler chicken were assigned to each treatment with eight birds in each. The birds fed 80 ppm Zinc of either GNZ or MNZ source resulted in significantly higher serum SOD, glutathione peroxidase, catalase, zinc, calcium, and phosphorus levels; increased bone dimensions, weight, total ash, phosphorus, and zinc content along with higher liver and muscle zinc concentration. The meat of chicken fed 80 ppm zinc of MNZ source followed by GNZ source has shown significantly better antioxidant (DPPH and ABTS values) status and lower lipid peroxidation (free fatty acid and TBARS values). The 80 ppm zinc of either MNZ or GNZ source resulted in significantly lower fat and cholesterol content of chicken meat compared to lower Zn levels and IZ source. This study indicated that 80 ppm dietary zinc of either MNZ or GNZ source improved the antioxidant status, and reduced the meat cholesterol, fat content, and lipid peroxidation of chicken meat along with increased bone dimensions and mineralization.

Impact of Dietary Organic Mineral Supplementation on Reproductive Performance, Egg Quality Characteristics, Lipid Oxidation, Ovarian Follicular Development, and Immune Response in Laying Hens Under High Ambient Temperature

The objectives of this study were to investigate the impact of dietary organic mineral mixture (manganese, zinc, and copper) supplementation on reproductive performance, egg quality characteristics, and immune response in laying hens under high ambient temperature. Hens were randomly divided into three treatments: (1) control (basal diet without organic mineral mixture (Mn, Zn, and Cu) supplementation); (2) basal diet + 0.5 g/kg of organic mineral mixture; and (3) basal diet + 1 g/kg of organic mineral mixture from 30 to 38 weeks of age. Hen-day egg production and egg mass were significantly increased by dietary supplementation of 1 g/kg of organic mineral mixture, while feed intake was not affected; therefore, feed conversion ratio (FCR) was significantly improved (P < 0.01). Egg weight, albumen width, shell weight, and shell thickness were significantly increased by the dietary treatments. Serum total cholesterol and glucose were significantly decreased by organic mineral mixture supplementation. Interestingly, yolk contents of total cholesterol and malondialdehyde (MDA) were significantly decreased. Yolk contents of Zn and Cu were significantly increased, while Mn was numerically increased (P > 0.05). Dietary organic mineral mixture supplementation improved the antibody titers against avian influenza H9N1 significantly (P < 0.05) and Newcastle disease virus numerically (P > 0.05) in comparison with the control diet. It might be concluded that the inclusion of organic mineral mixture (Mn, Zn, and Cu) enhanced reproductive performance, shell quality characteristics, plasma profile, yolk mineral concentration, yolk lipid oxidation, and immune response in laying hens under high ambient temperature.

Effect of zinc nanoaquacitrate on the biochemical and productive parameters of the organism of rabbits

Zinc is an essential microelement for the organism of animals, and its deficiency reduces the synthesis and degradation of proteins, lipids, carbohydrates and nucleic acids, and also decreases the metabolism of vital microelements. The objective of the study was determining the effect of various amounts of zinc nanoaquacitrate on the biochemical parameters of blood and productivity of the organism of rabbits after weaning on 50th to 86th days of life. Compared with the control group, intake of zinc nanoaquacitrate by the animals of the experimental groups exhibited dose-dependent effect on separate biochemical parameters which characterize the processes of lipid and mineral metabolisms, which manifested in the increase in their content in the blood on the 12th, 24th and 36th days of the experiment. Watering rabbits with zinc citrate in the dose of Zn 0.25 mg/kg after weaning determined its physiological effect on the biochemical parameters of their organism, expressed in the most statistically reliable changes compared with other tested amounts, particularly a higher level of the total protein, increase in the activities of glutathione reductase, alanine aminotransferase, catalase and alkaline phosphatase and decrease in the levels of cholesterol, lipid hydroperoxides, compared with the control, which may indicate the positive effect of the applied additives on certain biochemical parameters of the rabbits’ organism. Additional use of zinc citrate in the dose of 0.50 mg/kg of body weight was manifested in their blood by significant increase in the activities of catalase and glutathione reductase, lower level of lipid hydroperoxides and increase in the organism’s growth parameter by 3.1% in the final period of the study. Watering zinc citrate in the amount of 0.75 mg/kg of body weight provoked probable decrease in the level of cholesterol and triacylglycerols and increases in catalase and glutathione reductase, increase in activity of alanine aminotrasferase and decrease in lipid hydroperoxides, which determined the stimulating effect on the growth of the organism with 8.4% higher total gain of body weight after 36 days of the experiment. From a general perspective, the research indicates that intake of lowest amount of zinc citrate was characterized by the greatest effect on the biochemical blood parameters, whereas the use of greater amounts of organic compound of zinc showed positive effect on the processes of growth and development of the organism of rabbits after weaning. Of practical importance is the study of the effect of watering zinc nanoaquacitrate in the physiologically substantiated amounts on biochemical blood parameters and growth and survivability of the offspring and organism of the mother rabbit in the period of lactation.

Evaluation of Heavy Metal Content in Feed, Litter, Meat, Meat Products, Liver, and Table Eggs of Chickens

We assessed the concentrations of Fe, Cu, Zn, Mn, Se, Co, Cr, Pb, Cd, and Ni in chicken meat and meat products, feed, and litter, as well as laying hens' eggs, feed and litter to monitor the quality of products on the market and their safety for human consumption as judged by recommended daily allowance (RDA) and tolerable upper levels. Samples were chosen as the most popular poultry products in Saudi Arabia. A total of 45 broiler samples of frozen or fresh meat, liver, burger, or frankfurter were chosen from the same brand. Additionally, 60 table eggs from four commercial brands were collected, and the edible parts of these were used to determine levels of minerals and toxic elements. Furthermore, 30 feed and litter samples were collected from the starter, grower, and layer diets of broilers and laying hens. The results indicated that there were significant levels of most of the trace elements and heavy metals in the different meat sources. Furthermore, the liver contained the highest levels of elements, except for Cr, Co, and Ni. The highest Cr level was detected in the fresh meat, followed by frozen meat. Trace elements (Mn and Co) and heavy metals (Ni and Pb) were not detected in either the frozen or the fresh meat. The chicken burger and the frankfurter exhibited similar trace-element and heavy-metal contents, except for Zn and Mn, as the frankfurter showed higher concentrations than the burger. Differences in most of the trace and toxic elements among the different sources of eggs were not found to be significant, except for Zn. Differences between the broiler meat and table eggs were only substantial for Fe and Zn. Fe was significantly higher in meat than in eggs, and the opposite trend was found for Zn. The liver contained higher heavy metals than the eggs, except for Cr. In addition, the burger had higher concentrations of essential (Cu and Co) and heavy metals (Pb and Ni) than the eggs but had lower levels of Zn and Cr. The frankfurter exhibited significantly higher levels of Fe, Cu, Mn, Co, Pb, and Ni than the eggs but lower levels of Zn and Cr. To summarize, Cd, Pb, As, and Se were not detected in the broiler meat or eggs, indicating no risks from these toxic elements. Conversely, the liver exhibited the highest content of heavy metals, except for Cr, indicating that the intake of Pb and Cd was above the recommended daily allowance (RDA) for adults. The meat products exhibited higher Pb, Cd, and Ni levels than the broiler meat and the table eggs, suggesting that they posed a health threat to humans, and the intake of Pb in the meat products was higher than the RDA. Thus, chicken meat and table eggs, which are primary protein sources, are safe sources of human nutrition, while liver and meat products may present potential health hazards through the food chain.

Fatty acid profile, antioxidative status and dietary value of the breast muscle of broiler chickens receiving glycine-Zn chelates

In the present study we aimed to examine the effect of glycine-Zn chelates (ZnGly) used in amounts corresponding to 0, 100, 50 or 25% of the requirement of this element on the fatty acids profile, antioxidative status, and dietetic value (atherogenic index (AI), thrombogenic index (TI), hypocholesterolemic/hypercholesterolemic ratio (h/H)) of breast muscles in broiler chickens. Two hundred 1-day-old Ross 308 male chicks were split into four equipotent experimental groups (assigned to 20 cages, 10 chicks in each, replicated five times): control, ZnGly-100, ZnGly-50 and ZnGly-25. The broilers received feed and water ad libitum. The experiment lasted 42 days. Significant differences in the content of respective fatty acids in the meat of chickens receiving ZnGly were observed in comparison to the control group; but they were not directional changes. A positive effect (P &lt; 0.05) of Zn-Gly on certain indices of meat determined by the oxidoreductive status of the body or regulating such status was noted: superoxide dismutase, catalase and malondialdehyde. A significant effect of ZnGly on the dietetic value of broiler chickens’ breast meat was noted: the highest (P &lt; 0.05) AI value was found in the ZnGly-50 and ZnGly-25 groups, and TI value in the ZnGly-25 group. The h/H relationship can be presented as ZnGly-25 &lt; ZnGly-50 &lt; ZnGly-100 &lt; control group. To improve the dietetic value and to increase the oxidative stability of breast muscle meat, broiler chickens must receive ZnGly in an amount corresponding to more than 25% of the requirement of this element.

Supplementation of a water-soluble zinc-AA complex to reduce stress in broilers, pullets, and layers1

This study consisted of three 5-wk experiments to test the effects of administering Zinpro-LQ (Zinpro-LQ, Zinpro Corporation, Eden Prairie, MN) for different time intervals in stressed broilers, pullets, and layers. Treatments included: nonstressed control (NC), stressed control (SC), stressed and supplemented Zinpro-LQ for 14 d prior to stressor (S1), 10 d prior (S2), 7 d prior to and 7 d during stressor (S3), and 5 d prior (S4). Birds included 1-d-old Cobb 500 male broilers (Experiment 1), 7-wk-old white Leghorn pullets (Experiment 2), and 50-wk-old white Leghorn layers (Experiment 3). All stressed birds were vaccinated against Newcastle Disease Virus (NDV) on day 28 and exposed to random feed and water withdrawal days 28 to 35 for 6 h/d. Pullets were beak trimmed on day 21, and layers were heat stressed days 28 to 35. Blood was sampled on day 35 to determine plasma chemistry, corticosterone (CORT), anti-NDV antibody titer, and heterophil/lymphocyte (H/L) ratio. Mortality, feed and water consumption, and BW were also recorded. In Experiment 1, CORT and H/L ratio were highest in SC (P < 0.05). In Experiment 2, CORT was higher in SC than S4 (P < 0.05) while all other treatments were statistically intermediate. NDV titer was lower in SC than S4 while all other treatments were statistically intermediate. Treatment differences were also observed for H/L ratio, and plasma uric acid and cholesterol in Experiment 2. In Experiment 3, treatment differences were observed for H/L ratio, plasma glucose, sodium, and chloride. H/L ratio was lower in NC, S1, and S4 compared with SC (P < 0.05); and NC and S1 were lower than S2 (P < 0.05). In conclusion, dietary inclusion of zinc AA complex for any length of time prior to a stressor helped reduce measures of stress in broilers. The S1 and S4 treatments helped reduce stress and improve humoral immune response in pullets and layers.

Effects of Dietary Supplementation of L-Carnitine and Excess Lysine-Methionine on Growth Performance, Carcass Characteristics, and Immunity Markers of Broiler Chicken

L-carnitine as well as lysine and methionine are amino acids of important nutritional and nutraceutical interest and are used in nutritional strategies as diet supplements to improve feed quality characteristics in animals and broiler chicken in particular. This study investigated the effect of different levels of L-carnitine and extra levels of lysine-methionine on growth performance, carcass characteristics, and some immune system markers. Two hundred seventy male Ross 308 broilers were a fed control diet (C) and eight different diets supplemented with an excess of amino acids. In the experimental diets, identified as D1, D2, D3, D4, D5, D6, D7, and D8, extra L-carnitine, lysine, and methionine were added in excess with respect to the American National Research Council (NRC) recommendations: L-carnitine equal to NRC (D1); control diet supplemented with lysine at 30% in excess of NRC, methionine at 30% in excess of NRC, and L-carnitine equal to NRC (D2); control diet supplemented with lysine equal to NRC, methionine equal to NRC, and L-carnitine at 15% in excess of NRC (D3); control diet supplemented control diet supplemented with lysine at 15% in excess of NRC, methionine at 15% in excess of NRC, and L-carnitine at 15% in excess of NRC (D4); control diet supplemented lysine at 30% in excess of NRC, methionine at 30% in excess of NRC, and L-carnitine at 15% in excess of NRC (D5); control diet supplemented with lysine equal to NRC recommendations, methionine equal to NRC recommendations, and L-carnitine at 75% in excess of NRC (D6); control diet supplemented with lysine at 15% in excess of NRC, methionine at 15% in excess of NRC, and L-carnitine at 75% in excess of NRC (D7); and control diet supplemented with lysine at 30% in excess of NRC, methionine at 30% in excess of NRC, and L-carnitine at 75% in excess of NRC (D8). During the starter and growth phases, feed intake was not affected by dietary treatment (p > 0.05). By contrast, body weight and FCR were both affected (p < 0.001) during the starter period. During the finisher phase, feed consumption was affected (p < 0.05) by dietary treatment. Feed intake of broilers fed on C, D3, D6, and D7 were statistically similar (p > 0.05) (1851.90, 1862.00, 1945.10, and 1872.80 g/pen/day, respectively) and were higher (p < 0.05) than 1564.40 g/pen/day (D5). With the exception of drumsticks, neck, back thoracic vertebrae, and proventriculus weights, economical carcass segments were not affected (p > 0.05) by the dietary supplementation of amino acids. Duodenum and ileum weights and lengths decreased with amino acid supplementation (p < 0.05). IgT and IgG titers against Sheep Red Blood Cells (SRBC) for both primary and secondary responses were not affected by dietary treatments (p > 0.05). Dietary amino acids supplementation did not affect IgM titer after the secondary challenge (p > 0.05) and had a significant effect (p < 0.05) on serum antibody titers in broilers vaccinated against Newcastle disease (NCD) and Gumboro 's disease at the 27th and 30th days, respectively.